1. Field of the Invention
The present invention is directed towards a structural side rail for a dumping vehicle and a method to manufacture the rail. The present invention can be used on a tipper trailer, dump trailer or any other type of trailer or cargo box mounted on the back of a truck which needs a lightweight and strong structural member.
2. Prior Art
Tipper trailers are used to transport cargo, such as garbage or other materials, behind trucks or other vehicles. The cargo is dumped from a tipper trailer by moving the trailer onto a platform, detaching the truck, and then tilting the platform so that the front end of the tipper trailer is raised above the rear end, and the cargo slides out the rear end by the force of gravity. Unlike a dump trailer, the platform provides the tilting force to raise the trailer between the loading and unloading positions, whereas a dump trailer has a mechanism built into the trailer which can tip the trailer.
The sidewalls of tipper trailers are typically constructed from sheets of aluminum that are welded together along their sides so that a series of vertical seams are produced. The vertical seams provide wear points where a weakness can occur as the cargo slides over the sidewalls during dumping of a tipper trailer.
In the prior art, vertical rails have been placed over the seams to protect the seams from wear and also to provide support for the sidewalls. If the vertical rails are placed in the interior of a tipper trailer, they interfere with the discharge of the cargo during dumping. Typically, therefore, vertical rails are placed on the exterior of a tipper trailer so that the interior is smooth. Placing rails on the exterior of a tipper trailer results in a reduction of the interior volume available for cargo, since the overall width of the tipper trailer is limited by traffic laws. In addition, numerous vertical seams and vertical rails are required in the construction of a tipper trailer. Because the lengths of the sidewalls are typically many times their height, and the expense of welding numerous sheets of metal together and welding numerous rails onto the sidewalls significantly increases the cost of manufacturing a tipper trailer using vertical rails.
Also, in the prior art, the floor of a tipper trailer is constructed so that it is at a minimum height in order to accommodate the hitch (or fifth wheel) to the truck or other vehicle used to pull the tipper trailer. The floor is typically parallel to the ground throughout. The overall height, width, and length of the tipper trailer are all limited by traffic laws. Therefore, the height of the floor affects the interior volume and capacity of the tipper trailer for cargo.
Tipper trailers with horizontal ribs or rails were introduced as an improvement on tipper trailers constructed with vertical ribs.
In an effort to maximize the internal volume of the tipper trailer while minimizing the weight, it is possible to use a set of internal horizontal rails which add rigidity to the sidewalls of the trailer while providing a wear and tear resistance structure covering the seam and part of the sidewall of the tipper trailer. This also facilitates sliding of the cargo from the interior during dumping. One drawback of using the horizontal rails is that due to their long span, they have a tendency to flex outward when the tipper trailer is loaded. It is possible for the sidewalls of a tipper trailer constructed using horizontal rails to flex outward up to eleven inches when fully loaded. The horizontal rails were typically made from a single piece of extruded aluminum. Thus the horizontal rails must be made of an aluminum extrusion with very thick sidewalls. A center crossover brace can also be attached to the top center of the sidewalls in order to minimize the deflection of the sidewalls when the tipper trailer is loaded. However, the center crossover brace interfere with top loading the tipper trailer.
It is an object of the present invention is to reduce the thickness of the sidewalls of the horizontal rails while increasing the strength and rigidity of these rails.
It is a further object and purpose of the present invention to minimize the amount of weight of the horizontal rails.
It is yet a further object and purpose of the present invention to maximize the strength and rigidity of the tipper trailer side rails.
It is yet a further object and purpose of this invention to create a horizontal rail for a trailer which is sturdy enough that a center crossover brace is not required.
Other objects and further scope of the applicability of the present invention will become apparent from the detailed description to follow, taken in conjunction with the accompanying drawings wherein like parts are designated by like reference numerals.
The present invention is an improved rail for a tipper trailer. Tipper trailers are primarily used for transporting and dumping of materials such as garbage. The rail is constructed of an extruded piece of metal typically aluminum, although other metals or materials could be used. The rail has a slot running the length of it. A second piece, the insert, made of stronger material such as AR400 or 7005 aluminum, although other metals or materials could be used, is then inserted in the slot. The insert does not need to run the entire length of the rail but should run a substantial portion of the length of the rail and should be located in the center portion of the rail. The insert can be held in place by a number of apparatuses including a second piece of extruded aluminum used as a clip or a weld or combination of the two. If the extruded rail is aluminum and the insert is steel, the insert can be coated with a powder coating or galvanized in order to prevent corrosion inherent when steel and aluminum are in direct contact with each other. Under certain circumstances the slot can be coated with an adhesive prior to the insert being placed in the slot. The adhesive prevents the insert from coming in direct contact with the slot thus eliminating the need to coat the insert. The adhesive also provides a sufficient bond between the slot and the insert thus eliminating the need to use a retaining body such as a rod, clip or block welded to the interior of the rail, clip and/or weld to hold the insert in place. Also once the insert is in place the interior of the rail can be filled with a urethane foam to prevent air from coming in contact with the steel and aluminum interface in order to further prevent the possibility of corrosion. The rail is then welded into place, thus, sealing the interior of the rail from the atmosphere.